Many control approaches and schemes have been devised for internal combustion engines, particularly for large, relatively powerful diesel engines and engines running on other fuels. During periods of acceleration, a vehicle operator may command higher speed and/or torque from the vehicle, requiring higher output from the engine. In the case of rail vehicles and other transport vehicles, when steeper grades are encountered, additional torque or tractive effort is needed to maintain the speed of the vehicle, thereby increasing the power output demanded of the engine. As a result, during such a transient conditions, a greater amount of fuel may be injected to the engine; however, the fuel increase may not be immediately matched by a proportionate increase in air supplied to the engine. This may result in an air-fuel ratio that is too rich, leading to a decrease in engine speed, inefficient engine operation, and/or an increase in engine emissions.
In one approach, an engine system includes an air storage tank that delivers additional air to an intake manifold of the engine during transient conditions. As such, the cylinders of the engine may receive a greater air charge, resulting in a greater air-fuel ratio and faster torque increase. In such an example, however, there is a delay between a time a need for the additional air is determined and the time when the additional air is received by the cylinders due to, for example, a time it takes to fill the manifold with the additional air. As such, the cylinders may not receive the additional air for several engine strokes after the storage tank begins delivering the additional air to the intake manifold, thus delaying the response of the engine.